The gas that filled the electric bulb is:
- ANitrogen
- BHydrogen
- CCarbon Dioxide
- DOxygen
Solution & Step-by-step Explanation
Incandescent electric bulbs are filled with chemically unreactive or inert gases such as Nitrogen or Argon. These gases prevent the oxidation of the hot tungsten filament, thereby increasing the operational lifespan and safety of the bulb.